This contract is designed to study the simultaneous effects of various exposures to westernization, in this case to Israeli society, on changes in infant feeding patterns among a nomadic population experiencing sedentarization. The contractor was let persuant to an RFP which specified that the study has to be conducted in a population undergoing life-style transition and that the total population of women delivering newborns is accessible to be interviewed 24-72 hours after delivery. Analyses will be done in collaboration with NICHD to assess the effects of various exposures on infant feeding patterns.